ABSTRACT

A vector magnitude circuit (VMC) is one a circuit that receives two input voltages and produces an output voltage. The output voltage is the square root of the sum of the two squared input voltages. There are several applications of this circuit in measurements, instrumentation, and communication systems. Examples are (1) impedance and power measurements, (2) construction of signal envelope circuits, (3) diversity combiner circuits, (4) radiometer circuits, and other applications in which the power of separate waveforms must be added. Like a multiplier, a vector magnitude circuit is also classified as (1) a time division VMC, (2) a peak responding VMC, and (3) a pulse position responding VMC. The peak responding VMC is further classified as (1) a peak detecting VMC and (2) a peak sampling VMC. Various time division vector magnitude circuits using the 555 timer and analog multiplexers are explained in this and the next chapters.